Myelosarcoma preceding acute leukemia diagnosed by fine needle lymph node aspiration: report of two cases.

Myelosarcoma (granulocytic sarcoma) is a rare tumor seen in patients with known hematologic malignancies such as leukemia, myelodysplastic syndromes and myeloproliferative disorders, as well as in non-leukemic patients. A correct diagnosis in these cases is often difficult, and these are more commonly misdiagnosed as large cell lymphoma. We describe two women, 40 and 89 years of age respectively, in whom a myelosarcoma involving the neck lymph nodes was diagnosed by cytological examination of a fine needle aspiration biopsy, one and 10 weeks before the onset of acute myelogenous leukemia. The fine needle aspiration technique allowed a quick and unexpected diagnosis to be made demonstrating granulocytic differentiation and the presence of myelo-monocytic cells within lymphatic tissue. The simplicity of the procedure, coupled with its reliability and rapidity suggest that fine needle aspiration biopsies should be used more widely as a first choice method in the diagnostic evaluation of palpable lymph nodes.